Spray system



July 23, 1968 v R. .1. OTT v 3,393,658

SPRAY SYSTEM July 23, 1968 R. J. @TT 3,393,658

SPRAY SYSTEM Filed April 7, 1966 4 Sheets-Sheet 2 Wie/01@ J Mw, fi@a/wk, //Mgl July 23, 1968 R, 1. OTT 3,393,658

SPRAY SYSTEM y Filed April '7, 1966 4 Sheets-Sheet 3 Zag 314 i @Mm ma@www Magg R. J. OTT

SPRAY SYSTEM July 23, 1968 4 Sheets-Sheet t Filed April '7, 19663,393,658 Patented July 23, 1968 Uid Se@ Patent G 3,393,658 SPRAY SYSTEMf Richard J. Ott, Baroda, Mich., assgnor to Respond Inc.,

. Baroda, Mich., a corporation of Michigan Filed Apr. 7, 1966, Ser. No.540,874

11 Claims. (Cl. 1181-7) .ABSTRACT OF THE DISCLOSUREy There is disclosedan apparatus for -sprayinga release agent onto dies in a die-castingAmachine. The'apparatus includes a manifold structure carrying aplurality of spray guns and having internal passageways for releaseagent and air under pressure. The manifold structure is carried on theends of the piston rod and-a guide rod for movement between retractedand advanced positions. Control means responsveto movement of themanifold are provided for controlling the flow of air and release agent.

from the mold. In addition to increasing the lost time during aproduction operation a stuck casting is frequently damaged while beingremoved from the die and must be scrapped. To increase productionefficiency and to reduce the scrap rate itis a common practice to applya releasing agent to the-dies or molds. The releasing agent lubricatesadjoining surfaces of the mold andthe casting to prevent the castingfrom sticking to the mold.

A die or mold has a cavity Ain which the casting is formed. This diecavity commonly has a number of protuberances and indentations whichgive shape to a casting. The application of a releasing agent to all theirregular surfaces of the die cavityisusually accomplished by means of amanually actuated spray '.gun. To obtain complete coverage of theirregular die or mold surface the gun= is moved back and forth severaltimes while being tilted at various angles to the surface ofthe diecavity. After the mold has been covered with releasing agent in thismanner, the casting machine is actuated to continue the castingoperation.

Due to variations in the movements of the spray gun operator, the manualVapplication of releasing agent to a mold or die generally results in anuneven coating. Excess releasing agent is applied to parts of the diewhere the operator has moved the gun slowly. Conversely the coating ofreleasing agent will be skimpy and discontinuous at places where thespray gun is moved too rapidly. This uneven manual application ofreleasing agent to the mold results in increased production costs due tothe sticking of castings where the coating is too skimpy. orinterrupted. Production costs are further increased by the wasting oftime and releasing agent by the spray gun operator as he applies theagent. This loss of time and releasing agent results from needlessapplication of excess releasing agent to surfaces of the mold. Thus, theproduction efficiency of a highly developed die casting machine isgreatly reduced by the manual application of releasing agent to themolds by means of a single spray gun.

The spray gun itself commonly has a nozzle for directing a stream ofreleasing agent onto the surface of the die. The nozzle is usuallypositioned adjacent to the hot dies, immediately after forming acasting, to spray the die for the next casting operation. Elastomericseals in the nozzle soon deteriorate, due to the heat from the dies whenthe spray gun is used. Thus the efficiency of the prior art method ofapplying releasing agent to dies or molds is further reduced by the losttime required to periodically change the seals in the nozzle of thespray gun.

Therefore, one of the objectives of this invention is to provide a novelmeans for automatically spraying a releasing agent evenly and quicklyonto a die or mold cavity.

Another object of this invention is toreduce the quantity of releasingagent applied to a die when spraying the die.

Another object of this invention is to provide a spray gun nozzlesuitable for continuous use adjacent to a hot die.

Another object of this invention is to increase the production rate ofdie casting machines.

Another object of this invention is to provide a novel spray system toselectively apply a releasing agent to the irregular surfaces of a diecavity.

These and other objects and features of the invention will become moreapparent from a reading of the following detailed description taken incombination with the accompanying drawings wherein:

FIG. 1 is an elevational view of a die casting machine embodying theinvention;

FIG. 2 is a perspective view of the spray system utilized with the diecasting machine of FIG. l; f

FIG. 3 is a fragmentary detailed sectional -view of the carriage or boomfor the spray system of FIG. 2;

FIG. 4 is a fragmentary exploded view of the mounting means for thecarriage in FIG. 3;

FIG. 5 is a fragmentary sectional view taken along the line 5-5 of FIG.2;

FIG. 6 is a perspective view of a spray gun;

FIG. 7 is a fragmentary sectional view taken along the line 7-7 of FIG.6; and

FIG. 8 is a schematic drawing of the control system for the sprayassembly.

Referrng now to the drawings in greater detail, there is shown in FIG. 1a die casting machine 10 of a conventional construction. The die castingmachine 10 includes a stationary die or mold 12 and a movable die 14which cooperates with the stationary die 12. During the die castingoperation, the two dies 12 and 14 `are forced together by a hydraulictoggle mechanism 16. The toggle mechanism 16 will retain the dies 12 and14 in an abutting relationship. Molten metal is forced between the twoabutting dies 12 and 14 by means of a shot mechanism 18 which fills themating die cavities with a suitable metal for forming a casting. Theconstruction of the die casting machine 10, and the operation of theshot mechanism 18, is well known and does not per se constitute a partof this invention.

After an object has been cast between the two dies 12 and 14, the togglemechanism separates the dies and the casting is removed. As previouslyexplained, the hot casting tends to adhere to the surface of the dies 12and 14. To facilitate the removal of the casting from the dies, asuitable releasing agent is applied to the surfaces of the die cavities.A spray assembly 20 is utilized to apply the releasing agent to thesurfaces of the dies 12 and 14, so that the cast object can be readilyremoved from the dies.

Referring now to FIG. 2, the spray assembly 20 is fastened to the tiebars 22 `and 24 of the die casting machine 10 by means of a supportframe 26. The support frame 26 includes two vertically extending supportbars 2S and 30 which are interconnected by end plates 32 and 34. Thesupport frame 26 is connected to the tie bars by means of movableconnection assemblies 36 and 38. The connection assemblies are attachedto the tie bars 22 and 24 by roller chains 40 and 42. The roller chains40 and 42 are secured to the connection assemblies 36 and 38 by the nuts47 and bolts 48. When the nuts 47 and roller chains are loosened thesupport frame 26 can be moved horizontally to adjust the position of thespray assembly relative to the dies 12 and 14. It will also be apparentthat the adjustable roller chains 40 and 42 permit the spray assembly tobe easily connected to die casting machines having tie rods of differentdiameters.

' The connection assemblies 36 and 38 include sliding plates 44 and 46which are positioned intermediate the support bars 28 and 30. Backingplates 50 and 52 are fastened, by welding or other means, to the slidingplates 44 and 46. V-blocks 54 and 56 are connected to the backing plates50 and 52 by the bolts 60 and nuts 62. When the nuts 62 are tightened,the V-blocks 54 and 56 will clampingly engage the support bars 28 and30. By loosening the nuts 62 the support frame 26 can be moved up anddown to vary the vertical position of the spray assembly 20 relative tothe dies 12 and 14. This vertical adjustment f also permits the sprayassembly to be used with die casting machines having tie bars spacedapart by various distances.

From the foregoing remarks it is apparent that the support frame 26 canbe utilized to connect the spray assembly 20 to any desired die castingmachine. The roller chains 40 and 42 enable the connection assemblies 36and 38 to engage tie bars of various diameters on different die castingmachines. Since the support bars 28 and 30 may be adjusted vertically,relative to the connector blocks 36 and 38, the support frame 26 mayalso be attached to die casting machines having tie bars spaced apart byvarious vertical distances. If the spray assembly is to be used with adie casting machine which does not have tie bars, simulated tie lbarsmay be utilized for mounting the support frame 26 on the die castingmachine. This is done by the use of suitable cylinders which aresecurely connected to the die casting machine and act as substitute tiebars for mounting the spray assembly. Thus, the support frame 26 mayalso be connected to a die casting machine of a type which does notutilize tie bars.

The spray assembly 20 is mounted on a main frame 64 which is adjustablyfastened to the support bars 28 and 30 by means of the bolts 66 and 68which engage the slots 70 and 72 in the side of the main frame 64. Theslots 70 and 72 permit the main frame to be adjusted horizontallyrelative to the support bars 28 and 30. From an examination of FIG. 4,it will be apparent that the main frame 64 is advantageously made up oftwo identical support beams 76 and 78. The support beams are separatedby a central slot 80 which provides, as will be explained in greaterdetail subsequently, a means for mounting the drive mechanism for thespray system on the main frame 64.

v Referring now to FIG. 3, the drive mechanism includes an air cylinder82 which is connected to the main frame 64 by means of bolts 84 whichextend through the central slot 80 between the two support beams 76 and78. The air cylinder 82 has an outer end plate 86 and an opposite innerend plate 88 for closing the ends of the air cylinder 82. The two endplates 86 and 88 are clamped in a rm sealing engagement with the aircylinder 82 by means of tie rods 90. A piston 92 is slidable within theair cylinder 82 from a position adjacent the rear end plate 88 to aposition adjacent the forward end plate 86. A carriage assembly 94 isconnected to the piston 92 by means of a connecting rod 96. It will beapparent that forward and rearward movement of the piston 92 will alsomove a carriage assembly 94 relative to the air cylinder 82 and mainframe 64. The carriage assembly 94 is guided for forward and rearwardmovement by means of a support- 4 ing guidebar 98 which slides in acasing or cylinder 100 positioned immediately below the air cylinder 82.

The carriage assembly 94 includes a releasing agent or coating uidmaniflold 102 and an air or carrier fluid manifold 104. Spray guns 106and 108 are connected to the manifolds 102 and 104 by connections whichwill `be explained in greater detail subsequently. When the carriageassembly 94 is moved forwardly, by the connecting rod 96 and piston 92,the spray guns V106 and 108 will be positioned adjacent to the two `dies12 and 14 of the die casting machine 10. A cam rod 110 is connected tothe manifolds 102 and 104 and is moved forwardly with the spray guns 106and 10S. The cam rod 110l is guided by means of a guide block 112 whichis supported by the guide cylinder 100. The cam rod 110 has a pluralityof cam members' 114 mounted in a slot 115 in the cam rod 110. The cammembers 114 may, by loosening the connecting bolts 116, be adjustedrelative to the cam rod 110. The cams 114 actuate a limit or sensingswitch 118 which is fastened by a bracket to the end plate 86 of the aircylinder 82. The limit switch 118 is connected by suitable electricalleads 122 to a main control box 124 which is mounted on an outer end ofthe main frame 64 (see FIG. 1).

The mainv control box 124 coordinates and controls the movements of thecarriage assembly 94 and the actuation of the spray guns 106 and 108 bymeans of control valves and switch mechanisms. When the spray guns 106and 108 are 'actuated a coating fluid or releasing agent is applied tothe dies. The releasing agent is supplied, under pressure, to the sprayassembly 20 4by means of a suitable fluid passage or conduit 126 whichis connected to a pressurized source of releasing agent 128 (see FIG.8). A normally closed releasing agent solenoid valve 130 (see FIG. l) isconnected to the conduit 126 and a conduit 132 which extends from thesolenoid valve 130 to the releasing agent manifold 102. The solenoidvalve 130 controls the low of releasing agent between the conduit 126and the releasing agent manifold 102.

The solenoid valve 130 is connected to the main co'ntrol box 124 bymeans of a suitable electrical connection 134. When the limit or sensingswitch 118 is actuated by one of the cams 114, the normally lclosedsolenoid Value 130 will be opened to enable the releasing agent orcoating fluid to flow through the conduit 132 to the releasing agent orcoating fluid manifold 102. The releasing agent or coating Huid isconducted from the manifold 102 to the spray guns 106 and 108 by theconnecting conduits or hoses 136 and 138. As will be explained ingreater detail subsequently, when the sensing switch 118 is actuated byone of the cams 114 the spray guns 106 and 108 will be in a sprayposition, relative to the dies 12 and 14. The opening of the solenoidvalue 130 will then allow the pressurized releasing agent or coatingfluid to be conducted to the spray guns 106 and 108 onto the dies at thepredetermined spray location.

When the spray guns 106 and 108 are not in a spray position, they willnot spray releasing agent or coating uid onto the dies since the supplyof releasing agent is cut olf by the closing of solenoid valve 130.Thus, the cams 114, which actuate the limit or sensing switch 118 whenthe spray guns are in a spray position, permit the spray assembly toonly spray the dies with releasing agent at predetermined locations. Itwill be apparent that this feature will reduce production costs byreducing the wastage of releasing agent or coating liuid.

The carriage assembly 94 is moved into the spray position, relative tothe dies 12 and 14, by the piston 92 which is forced forwardly by `airpressure on a rear surface 140 of the piston. The piston 92 and spraycarriage assembly 94 are moved rearwardly by air pressure on a forwardsurface 142 of the piston. High pressure air, to move the piston 92, isconducted to the aircylinder 82 from a suitable source 143 by means ofthe pipe or conduit 144. The pipe orconduit 144 is connectedvto the airsupply control valve146 by means of a T-connection 148 and conduit 150.-In a manner to l:be .explained in greater detail subsequently, thecontrol valve 146 selectively `directs the airpressure into either theconduit or air hose 152 which is connected vtohthe rear of the aircylinder 82 or the conduit 154 which is connected to the forward end ofthe air cylinder 82. It will be apparent that when the control valve-146 directs the high pressure air through the conduit 152 to the rearof the air cylinder 82, the piston 92 will be forced forwardly by airpressure on the rearsurface 140 of the piston. When the air is conductedthrough the conduit 154 it will be directed against the forward surface142 of the piston 92 to move the carriage assembly and piston rearwardlyrelative to the main frame64. t

The air control valve 146 is a two-way valve which is actuated by meansof a solenoid 156 which is connected to the main control box 124 by asuitable electrical connection 158. When the air control valve 146isactuated to direct the high pressure air through the conduit 152 tothe rear of the piston 92, the conduit l154 lwill be connected to anexhaust port 160.` Thus, the air between the forward surface 142 of thepiston and the end plate 86 of the air cylinder 82 will be returned tothe air control valve 146 -by the conduit 154 and exhausted to theatmosphere through the exhaust port 1.60. When the forward portion ofthe cylinder is at the relatively low exhaust or atmospheric pressure,the piston 92 will move forward under the force of the high pressure airagainst the rear surface 140y of the piston. When the air control valve146 is returned to its normal or unactuated position, the conduit 152will be connected to the exhaust port 160. The high pressure air, fromthe conduit 150', will then be directed through the conduit 154 to theforward end of the air cylinder 82 to apply air pressure against theforward surface 142 of the piston. The high pressure air on the forwardsur-face 142 of the piston will force the piston and carriage assembly`94 rearwardly to the return or starting position. The air between therear surface 140 of the piston 92 and the end plate 88 will beconducted, through the conduit 152, to the exhaust port 160 to permitthe piston 92 to move rearwardly.

The rate of movement of the carriage assembly, relative to the mainframe 64, is controlled by means of a throttle valve 164 and a normallyopen speed control valve 166 (see FIG. 8). The forward end of the aircylinder 82 is connected to the throttle valve 164 by air conduits 168and 170. The air cylinder is also connected to the speed control valve166 by means of a conduit 172. It will be apparent from an examinationof FIG. 8 that the speed control valve 166 and throttle valve 164 areconnected in a parallel relationship by means of the conduits 174 and176.

The adjustable throttle valve may be set to permit a predeterminedquantity of return air to flow through the conduits 170 and 176 to thereturn conduit 154. When the normally open speed control valve 166 isactuated to the closed position, it will be apparent that the setting ofthe throttle 164 will regulate the rate of ow of return air, andtherefore the speed with which the piston 92 can be driven forward bythe high pressure air on the rear surface 140 of the piston. Thethrottle valve 164 is set to restrict the flow of return air frombetween the forward surface 142 of the piston 92 and the end plate 86 ofthe air cylinder 82. The resulting low piston speed, as will beexplained in greater detail subsequently, corresponds to a relativelyslow spray speed. Thus, the carriage assembly 94 will, when the speedcontrol valve 166 is closed, move forwardly at a relatively slow speedto permit the spray guns 106 and 108 to thoroughly coat the dies withthe releasing agent or coating uid.

When the carriage assembly 94 is being returned to its original positionafter spraying the dies, and during the non-spray forward movement ofthe carriage assembly,

tha-t is when the cams 114 are not in actuating contact with the sensingswitch 118, the carriage assembly is moved at a relatively high traversespeed. When the carriage is moving at this relatively hightraversespeed, the speed control valve 166 is open to enable the returnair to flow through the conduits 172 and 174 to the return conduit 154.It will be apparent that when the speed cont-rol valve 166 is open thereturn air can be conducted from the forward part of the air cylinder 82at a much greater rate. Therefore, the ,piston 92 will move forward at ahigher speed under the force of the high pressure air on the rearsurface of the piston 92.

From the foregoing remarks, it will be apparent that the rate ofmovement of the carriage assembly 94 is controlled by regulating thellow of return air from the cylinder 82. When the flow of return airfrom the cylinder 82 is restricted by the adjustable throttle valve 164and the speed control valve 166 is closed, the carriage assembly willmove at a relatively slow spray speed. When the speed control valve 166is open, the flow of return air will, to some extent, bypass thethrottle valve 164 so that the carriage assembly 94 will move at arelatively high traverse speed. Thus, the time required for a spraycycle is held to a minimum by enabling 'the carriage to move at a firstrelatively high speed to the spray position, then reducing its rate offorward movement during the spray operation. After the dies have beensprayed the carriage is returned to its initial position at therelatively high traverse speed.

To coordinate the rate of movement of the carriage 94 with the positionof the spray guns 106 and 108 relative to the dies, the speed controlvalve 166 is actuated by the closing of the limit or sensing switch 118by the cams 114. The cams 114 are positioned on the cam rod 110 atpredetermined locations so that the carriage and spray guns will be in aspray position relative to the dies when the sensing switch 118 isactuated. As previously explained, the closing of the sensing switch 118also actuates the normally closed releasing agent solenoid valve 130.Thus, the closing of the sensing switch slows the rate of movement ofthe carriage 94 from the traverse speed to the spray speed Whilesimultaneously opening the releasing agent solenoid valve 130 to enablereleasing agent to be conducted to the spray guns 106 and 108.

In addition to supplying air for moving the carriage assembly 94, theair conduit or hose 144 conducts air to a normally closed spray airsupply control valve by a conduit 182. The spray air supply controlvalve 180 is connected to the air manifold 104 by a conduit 184. Whenthe normally closed spray air supply control valve 180 is opened, highpressure air will ow from the conduit 144 through the valve to themanifold 104. As will be explained in greater detail subsequently, theair will then flow from the manifold 104 to the spray guns 106 and 108to entrain the releasing agent or coating uid for application to thedies. The actuation of the spray air supply control valve 180 iscontrolled by the solenoid 186 which is connected to the main controlbox 124 by the electrical connector 188. When the air supply valve 186is in its normal or closed position, the air manifold 104 will not bepressurized and the spray guns 106 and 1108 will not napply coatingfluid or releasing agent to the ies.

The actuation of the releasing agent flow control solenoid valve 130,the air supply control valve 146 and the spray air supply control valve180 are all coordinated by the main control box 124. The main controlbox 124 senses the position of the carriage assembly 94 relative to themain frame by means of the sensing switch 118 which is connected to themain control box by the electrical leads 122. Referring now to FIG. 8,the main control box 124 is supplied with power by lines 190 and 192which are connected to terminals 196 and 198 of a terminal block 194. Tobegin the spray cycle a start switch, not shown, is actuated by theoperator of the die casting machine. The start switch is connected bymeans of leads 200 and 202 to the terminals 204 and 206 of the terminalblock 194. A timer 208 is connected to the power line 190 by means of alead 210 which is connected to a terminal 211 of the timer and terminal212 and terminal block 194. Terminal 214 of the timer 208 is in turnconnected to the limit switch 118 and air supply control valve 146 bymeans of the leads 216, 218 and 220. The terminal 214 of the timer isalso connected to a terminal 222 of a selector switch 224 by a lead 226.It will be apparent that actuation of the timer 208, to interconnectterminals 211 and 214, is necessary to complete the circuit from thepower line 190, through the solenoids for the control valves to thepower line 192.

The timer 208, of a known construction, may be set for any predeterminedtime, during Iwhich the terminal 211 will be connected to the terminal214 by the timer switch 230. At the end of the predetermined time, thetimer 208 will open a switch 230 so that the terminal 214 is no longerconnected to the terminal 211. When the switch 230 is opened, thevarious control solenoids will be released and the control valves will'be returned to their normal position.

The limit or sensing switch 118 is connected by the leads 232, 234 and236 to the releasing agent supply control valve 130. The releasing.agent supply control valve 130 is in turn connected by the lead 240 tothe power line 192 through terminals 228 and 198 of the terminal block194. Actuation of the normally open limit switch 118, will close thecircuit between the two power leads 190 and 192 to actuate the releasingagent control valve 130.

The limit switch 118 is connected by means of leads 232 and 241 to thecarriage speed control valve 166. The carriage speed control valve 166is connected to the terminal 238 of the terminal block 194 by means ofthe leads 242 and 248. The limit Switch or sensing switch 118 is alsoconnected to the spray air supply control valve 180 through the selectorswitch 224 by means of the leads 232, 234, 250 and 252. The leads 250and 252 are interconnected, at the selector switch 224, by means of theswitch bar 254 and the contacts 256 and 258. When the selector switch ismoved to the left the limit switch 118 `will be connected to the sprayair supply control valve 180. The spray air supply control valve 180 isalso connected to the power line 192 by means of the leads 260 and 248.

The above circuitry interconnects the components of the spray assemblyso that closing of the limit switch 118 by the calms 114 willsimultaneously cause the a-ctuation of the liquid solenoid valve 130,the spray air supply control valve ,180, and the cylinder speed controlvalve 166. Since the cams 114 have a length corresponding to theduration of a spray period and are located :to actuate the switch whenthe spray guns are in a spray position, it lwill be apparent that theclosing of the limit switch will occur only at spray positions for :apredetermined spray period. During the spray period releasing agent willbe supplied to the spray guns 106 and 108 through the actuated releasingagent control valve 130. High pressure air will simultaneously besupplied to the guns by the actuation of the spray air supply controlvalve 180. The speed control valve 166 is closed so that the carriagetravels at a relatively slow rate during the spray period. The limit orsensing switch 118, by sensing the positioning of the carriage assemblyin a predetermined spray position, coordinates the conducting ofreleasing agent and the air to the spray guns 106 and 108 whilesimultaneously reducing the rate of travel of the carriage assembly 94.

The air supply control valve 146 is connected to the timer 208 by theleads 216 and 220. The air supply control valve 146 is also connected tothe power line 192 by means of the leads 264 and 248. Thus, the airSupply control valve 146 will be actuated to supply high pressure airagainst the rear surface of the piston 92, through the conduit 152whenever the timer switch 230 is closed. When the timer switch 230opens, at the end of a predetermined time the air supply control valve`146 will be released .and the carriage 94 will be returned to its normalposition by high pressure air which will be connected to the forward endof the air cylinder 82 by means of the return air conduit 154.

When the selector switch 224 is placed with the selector bar 254 betweencontacts 266 and 222, that is with the selector switch moved to theright of the position shown in FIG. 8, the spray air supply controlvalve will be connected to the power line through the leads 252, 226 and210. Since the other side of the spray air supply control valve 180 isconnected directly to the power line 192 -by the leads 260 and 248, thespray air supply control valve 180 will be continuously actuated whenthe timer 208 is closed. Thus, a continuous stream of air will ow out ofthe spray guns 106 and 108. The releasing agent or coating fluid will-be controlled by the solenoid 130 which is actuated in response to thelimit switch 118 sensing a spray position. The continuous flow of air,when the selector switch is across contacts 266 and 222, will cool thehot -dies while the carriage assemly is moving at the relatively hightraverse speed to a spray position. When an intermittent air supply isdesired, the selector switch 224 may be moved across contacts 256 and258, so th-at the sensing or limit switch 118 must be actuated in orderto complete the circuit through the spray air supply control valve.

Referring now to FIGS. 3, 6 and 7, high pressure air is supplied to thespray guns 106 and 108 through the air manifold 104. The spray guns 106and 108 are connected to the air manifold 104 by means of a universalmounting 270. The universal mounting 270 is connected to the -manifold104 Iby a' threaded connector tube 272 which is screwed into an aperture274 in the manifold. The threads 276 on the connector tube 272 mate withthreads on the interior of the aperture 274. When the connector tube 272has been threaded into the aperture 274, a jam or lock nut 278 istightened to secure the connector tube 272 in position. A fitting orelbow 280 is fastened to the opposite end of the connector tube 272. Asecond, upwardly directed, connector tube 282 is connected to thefitting 280 and is threaded into an aperture 283 in the body member 284of the spray gun. The connector tube 282 is locked into position bymeans of the jam or lock nut 288. A channel or passage 290 is providedin the center of the connector tubes 272 and 282 and the fitting 280.The channel 290 will conduct high pressure air from the manifold 104into the body 284 of the spray gun.

The spray gun may be pointed in any desired direction by adjusting theuniversal connection 270. It will be apparent that the spray gun, asshown in FIG. 6, may be pointed downwardly by pivoting the universalconnection 270. The universal connection 270 is pivoted, relative to themanifold 104, by loosening the jam or lock nut 278 and turning theconnector tube 272 in the threaded aperture 274. When the spray gun ispointed in the desired direction, the lock nut 278 is tightened toretain the connector tube 272 and the spray gun in the desired position.In a similar manner, the spray gun may be adjusted to point in anyhorizontal direction, as viewed in FIG. 6, by loosening the lock nut 288and moving the body member 284 on the threaded end portion of theconnector tube 282. When the spray gun has been pointed in the desiredhorizontal direction, it will be apparent that it can be locked in thatposition by merely tightening the lock or jam nut 288.

As is best shown in FIG. 7, the spray gun includes a forward nozzlemember 292 which is connected to the body 284 by means of threads 294 inthe end portion of the nozzle. The threads 294 mate Withthreads 296 onthe interior of an aperture 298 in the body member 9 284. The nozzle 292includes a frustoconically shaped mouth or orifice 300 which has a baseportion 302 and a head portion 304. A channel or passage 306 isconnected to the head portion 304 of the mouth 300. A cylindricalchamber 308 is defined by a side wall 310 connected to a base wall 312and the base 302 of the frustoconical orifice 300 of the nozzle 292.From an inspection of FIG. 7, it will be apparent that air from themanifold 104 will flow through a passage 290 to the chamber 30S. The airwill then flow through the base 302 of the nozzle 292 to the channel306. When the air flows from the frustoconically shaped mouth or orifice300 into the channel 306, a releasing agent will be entrained in the airin a manner to be explained in greater detail subsequently.

The spray gun is supplied with releasing agent, as previously explained,by the conduit 136 which is connected to the releasing agent manifold102. The releasing agent will flow from the conduit 136 through a valve314 into a chamber 316 in the body member 284 of the spray gun. Thereleasing agent chamber 316 is connected to -an expansion tube 318 bymeans of the nozzle or orifice 320. The nozzle or orifice 320 isfrustoconical in shape and has a head portion 322 connected to thechamber 316 and a base portion 324 abutting the expansion -tube 318. Itwill be apparent that the releasing lagent will fiow through the tube136 and the valve 314 into the chamber 316. The pressurized releasingagent will then flow from the chamber 316 through the head 322 of thenozzle or orifice 320 into the expansion tube 318. Since the nozzle 320is frustoconical in shape, the releasing agent will tend to atomize whenit flows from the chamber 316 to the expansion tube 318 through thenozzle 320. The atomized releasing agent will fiow through the tube 318into the channel 306 inthe nozzle 292. The atomized releasing agent willbe entrained, in the channel 306, in the air flowing from the chamber308 through the nozzle 292. The entraining of the releasing'agent, inthe -air which acts as a carrier fluid, is facilitated by an expansionarea 330 in the end portion of the tube member 318. v

The valve 314 includes a ball check 332 which is seated against theconduit fitting 334 by the spring 336. The pressure exerted on the ballcheck 332 by the spring 336 can be varied by turning the adjustmentscrew 338. When the adjustment screw 33-8 is turned `downwardly thespring will exert a greater pressure seating the ball check on thefitting 334. Similarly, if the' adjustment screw 338 is unscrewed orturned upwardly, the spring 336 will exert less pressure on the ballcheck 332. When the adjustment screw 338 has been positioned to give thedesired seating force on the Iballcheck 332, the jam or lock nut 340 istightened to retain the adjustment screw in the desired position.

If the pressure on the releasing agent or fluid coating in the conduit136 is insufficient to overcome the spring pressure on the ball check332, it will be apparent that the valve 314 will prevent the -releasingagent or coating fluid from flowing into the chamber 316. Thus, the flowof the releasing agent, through the spray gun, will be controlled byboth the valve 314 and the releasing agent control solenoid valve 130.The spray gun may also be utilized with ya system which does not supplyreleasing agent or coating fiuid under pressure. When used with suc'h asystem the adjustment screw is positioned to apply a very light pressureon the ball check 332. When this is done air flowing through the nozzle292 will draw or Siphon the releasing agentfromthe chamber 316 and theconduit 136 through the expansion tube 318. The siphoned releasingagentor coating fluid will be entrained in the high pressure air,flowing aroun-d the expansion tube 318, in the manner previouslyexplained for a system utilizing apressurized source of releasing agentor coating fiuid.

The spray gun, as will be seen in FIG. 7, does not require the use ofany elastomeric seals in order to obtain a fluid tight connectionbetween the various components of the spray gun. The Aexpansion tube 318is forced into a 10 circular aperture 342 in the' body member 284. The.various other threaded connections are all tightened to form a seal sothat they do not leak. Since there are no elastomeric seals in the spraygun, it will be apparent that the gun may be utilized in a relativelyhot environment for a long period of time. Thus, the heat from the dies12 and 14 of the die casting machine 10 willnot, after a relativelyshort period of use, cause leaks at the joints between the components ofthe spray guns 106 and 108.

For purposes of affording a more complete understanding of theinvention, it is advantageous now to provide a functional description ofthe mode in which the component parts thus `far identified cooperate.The spray assembly support frame 26 is clamped to the tie bars 22 and 24of the die casting machine 10. The main frame 64, which is connected tothe vsupport frame 26, positions a carriage assembly 94 adjacent to thedies 12 and 14 of the die casting machine 10. The support frame 26 canbe adjusted vertically, by means of the connection assemblies 36 and 38to position the spray guns 106 and 108 adjacent to the center of thedie. The two slots 70 and 82 enable the main frame 64 and spr-ay guns to-be adjusted horizontally relative to the dies 12 and 14.

`When a suitable starting switch, not shown, is actuated, the air supplycontrol valve 146 will be actuated to connect air from the high pressureair supply conduit 144 to the conduit 152. The conduit 152 is connectedto the rear end the air cylinder 92 so that the high pressure air willforce the piston 92 to move forwardly in the cylinder 82. The returnair, from the forward end of the cylinder 82 will then ow through theconduits 168, and 172 to the speed control valve 166 and throttle valve164 (see FIG. 8) and into the return air conduit 154. When the two-wayair supply control valve 146 was actuated to connect the high pressureair to the conduit 152, the return air con-duit 154 was connected to theexhaust port 160 of the control valve. Thus the .return'ai'r will owfrom the return air conduit through the exhaust port into the atmosphere`as the piston moves forward.

The carriage assembly 94 and the piston 92 will move forwardly until thespray guns 106 and 608 are adjacent a portion of the dies which is to besprayed. When this predetermined spray position is reached, the sensingswitch 118 will 4be actuated or closed by contacting a cam 114. When theswitch 118 is closed, the speed control valve 166 will be closed toblock the flow of air from the conduit 172 to the conduit 174. Thereturn air from the air cylinder 82 will then be able to fiow onlythrough the throttle valve 164. Thus, the rate of forward movement ofthe piston 92 and the carriage assembly 94 will be reduced and thecarriage will slow down to a predetermined spray speed which can beadjusted by means of the throttle valve 164.

In addition to reducing the rate of forward movement of the carriageassembly, the closing of the limit switch 118 actuates the releasingagent or coating fiuid control valve 130 to enable the pressurizedreleasing agent or coating fiuid to flow through the conduits 126 and132 to the releasing agent manifold 102. The pressurizedreleasing agentor coating fiuid will flow from the manifold 102 through the conduits136 and 138 to the spray guns 106 and 108. Simultaneously with theactuation of the releasing agent control valve 130 a spray air supplycontrol valve will be actuated by the closing of the sensing switch 118.When the spray air supply control valve 180 is actuated, high pressureair will then fiow through the conduits 144 and 184 to the air orcarrier fluid manifold 104.

The air or carrier fluid manifold 104 is connected to the spray guns 106and 108 through the passages 290 in the universal mounting 270. Thereleasing agent or coating fiuid will be entrained in the high pressureair or carrier fiuid in the nozzle 292 of the spray guns 106 and 108.The entrained releasing agent will be sprayed onto the dies 12, 14 bythe spray guns 106 and 108. It should be realized that while only twospray guns 106 and 108 have been shown, it is contemplated that anydesired number of spray guns can be connected to the air manifold 104 byremoving plugs 400 and mounting air guns in the apertures in the airmanifold 104. Similarly, plugs 402 are provided for apertures in thereleasing agent manifold 102. Thus, additional releasing agent conduits,similar to 132 and 136, could be connected to the added spray guns toconduct releasing agent from the manifold 102 to the spray guns.

When the cams 114 are moved out of contact with the sensing switch 118,the carriage assembly will have moved past the spray position and thesensing switch will open, When the sensing switch 118 has opened, thereleasing agent control valve 130 and spray air supply control 180 willbe closed. Thus, the spray guns 106 and 108 will, when the carriageassembly 94 moves past the spray position, stop spraying releasing agenton the dies 12 and 14. Simultaneously with the release of the controlvalves 130 and 180, lthe speed control valve 166 will be opened. Thereturn air, from the air cylinder 82, will then flow through theconduits 172 and 174 to enable the piston 92 to travel at a higherforward speed in the air cylinder 82. The carriage assembly 94 willcontinue to move at this relatively high traverse speed until the limitswitch 118 again contacts a projecting cam 114.

It will be apparent that the duration of the spray period of any givenspray position will be determined by the length of the cam 114. Sincethe cams 114 may be of any desired length, the spray period at each ofthe spray positions may be of any desired duration. The cams 114 arealso independently adjustable longitudinally on the cam rod 110 to varythe location of a spray position relative to the dies 12 and 14. Thus,the spray positions may be adjusted so that the spray guns 106 and 108will apply the releasing agent to die cavities having any shape inaccordance with the object to be cast.

A timer 208 is connected to the air supply control valve 146. When thetimer indicates that a predetermined time period has elapsed, the timerwill open to break the circuit retaining the air spray control valve 146in open or forward position. The air supply valve 146 will, when thetimer 208 breaks the circuit, be actuated to connect the forward airsupply conduit 152 to the exhaust port 160 and the rearward air supplyconduit 154 to the source 143 of high pressure air. The high pressureair will then travel through the conduits 154, 174 and 176 and thethrottle valve 164 and speed control valve 166 to the forward end of theair cylinder 82. The high pressure air will contact the forward surface142 of the piston 92 to move the piston rearwardly in the air cylinder82. rlChe piston 92 will return to the original or starting positionadjacent to the end plate 88 of the air cylinder 82 until the next spraycycle. The carriage assembly, in the original or starting position, willbe spaced apart from the dies 12 and 14 so that the die casting machinecan bring the two dies together for a die casting operation.

A continuous flow of spray air, through the control valve 160 may beapplied to the air or carrier fluid manifold 104 by placing the selectorswitch 224 across contacts 222 and 266. When the selector switch is inthis position a continuous stream of cooling air will be applied to thesurface of the hot dies on both the outwardly and inwardly movements ofthe carriage assembly 94. When the selector switch 224 is placed acrosscontacts 256 and 258, the spray air supply control valve 180 will beactuated, as previously explained, when the sensing switch 118 is closedby the cams 114. Thus, with the selector switch in this positiontherewill be an intermittent flow of carrier fluid or air from the spray guns106 and 108 at only the spray position when the coating fluid orreleasing agent will be entrained in the air by the spray guns.

The spray guns, which may be of any desired number by merely mountingadditional guns in place of the plugs 400 in the air manifold 404, areconnected to the air manifold 104 by means of a universal mounting 270.The universal mounting permits the guns to be pointed in any desireddirection to provide an optimum angle of contact for the stream ofair-entrained releasing agent to contact the dies 12 and 14. It will beapparent that this feature is particularly useful with a deep die havingangled surfaces.

The spray guns are made of metal parts which are heat resistant. Theheat from the hot dies will not therefore deteriorate the joints betweenthe components of the spray gun. Thus, the spray guns can be utilizedfor a relatively long period of time without replacing any of thecomponent parts. f

Although the preferred embodiment of the invention has been shown with acarriage mounted in a horizontal position, it -Will be apparent to thoseskilled in the art that the spray assembly could be mounted with thecarriage assembly in the vertical position. Also, while a fluidreleasing agent has been found to be most satisfactory for mostapplications to dies, it is contemplated that a powdered releasing agent`could be used with the spray assembly. In addition to thesemodifications, it will be apparent to those skilled in the art that thespray will have applications in environments other than die casting.Thus, a coating fluid, other than a releasing agent, could be applied bythe spray guns 106 and 108 to a given object. The spray guns are capableof entraining any desired coating fluid in a given carrier fluid.

In view of the foregoing remarks, it shoul-d be understood, that theinvention is not limited to the particular embodiment shown. These andmany other modifications may be made; and it is, therefore, contemplatedto cover by the appended claims any such modifications as fall withinthe spirit and scope of the invention.

What is claimed is:

1. An apparatus for applying a lrelease agent to dies in a die-castingmac-hine comprising a frame mountable a'djacent a die-casting machine,manifold means including a first portion connectable to a source ofrelease agent and a second :portion connectable to a source of air underpressure, spray gun means mounted on said manifold means and connectedto said release agent portion and said air portion, a pair of parallelspace-d apart elongated rod-like members `reciprocably mounted on saidframe and connected to and supporting said manifold means for movementbetween a retracted position and advanced spraying positions laterallyoutwardly from said frame and adjacent said dies, drive means connectedwith one of said members for selectively advancing and -retracting saidmembers and said manifold means, an elongated cam support memberparallel to said rod-like members and connected for movement in unisonwith said manifold means, cam means on said cam support member, andcontrol means for controlling said drive means and flow of release agentand air to said manifold means and including a sensor mounted on saidframe and engageable with said cam means.

2. An apparatus, as defined in claim 1, wherein said cam means includesa plurality `of independently adjustable cams, each of said camsrepresenting a predetermined spraying position, and said sensorcomprises a single sensing switch actuated by said cams upon movement ofthe manifold means to said predetermined spraying positions.

3. An apparatus, as defined in claim 2, wherein said switch is a doubleacting switch -responsive to b-oth advancing and retracting movements ofthe manifold means.

4, An apparatus, as defined in claim 1, wherein said control meansincludes an air control valve connected between the source of air underpressure and said air rportion of the manifold means, a valve controlconnected to said valve to actuate the valve from a first closedposition to a second open position, and selector means connected to saidvalve control and actuatable from a first selector position to asecondselector position, said valve control being connected to saidsensor when said selector meansv is in said first position so that.saidvalve will be actuated from the closed position to the 4openposition when said sensor indicates the spray gun means to be inaspraying position, said valve means being held contiuuously in saidopen position by the valve control when saidV selector meansis in saidsecond position.

5. An apparatus, as defined in claim 1, whereinsaid controlmeans-includes timer means for actuating said drive means to move saidspray lgun means from an advanced spraying position to said retractedpositionat the end of a predetermined time.

- 6. An apparatus, as defined in claim 1, wherein said release agentportion of the manifold means comprises a block-,like .member having apassageway therein with a plurality of outlet ports, said air portionofthe manifold means comprises a rigid tube structure secured to saidblock member and having. an internal passageway with a plurality ofAoutlet ports, said spray gun means comprises a pluralityof separatespray guns, saidZ apparatus including fitting means rigidly andadjustably mounting said spray guns of said air manifold tube structureand respectively connecting spray guns to the outlet ports of the airpassageways, and a plurality of conduits respectively connecting sprayguns to the outlet ports of said release agent passageway.

7. An apparatus, as defined in claim 6, wherein sai-d block membertraverses and is secu-red to ends of said elongated rod-like members andsaid cam support member.

8. An apparatus, as defined in claim 1, wherein said frame comprises la-frame member disposed transversely with respect to said elongatedrod-like members and extending outwardly in opposite directionstherefrom, and attachment means on opposite end portions of said framemember for secu-ring said frame to tie-rods of a die-casting machine.

9. An apparatus for spraying material such as a release agent ontoworkpieces such as dies in a die-casting machine comprising a framemountable adjacent a diedcasting machine, an elongated air cylindermounted on said frame, an elongated piston rod telescopically associatedWith and operable by said cylinder and having an outer end piroL jectinglaterally of said frame, 4a guide rod reciprocably mounted on said framein parallel spaced relationship with respect to said piston rod, amanifold block connectedto and carried by outer ends of said rods yandhaving intern-al passageway means including an inlet port connectablewith a source of release agent and a plurality of outlet ports, a rigidtube manifold structure secured to and carried by said block and havingan internal passageway with an inlet port connectable with a source ofair under pres'- sure and a plurality of outlet ports, a plurality ofspray guns each having a release agent inlet port and an air inlet port,a plurality of pipe fitting means rigidly and adjustably mounting saidspray guns on said tube manifold structure and connecting the outlet airports of said manifold structure with the inlet air fports of the sprayguns, and a plurality of flexible conduits respectively connecting theoutlet ports of said block manifold member lwith the release agent inletports of the spray guns.

10.- An apparatus, as defined in claim 9, which includes an elongatedcam support member parallel to said rods and connected with said blockmember, said support member having a longitudinally extending slottherein, cam means adjusta-bly mounted in said slot on said supportmember, and control means mounted on said frame for controlling the flowof the release agent and air to said spray guns, said control meansincluding a sensor en-gageable with said cam means.

11. An apparatus, as defined in claim 10, wherein sai-d cam supportmember and said cam means are disposed over said rods and substantiallyover said frame in an exposed position for facilitating adjustment ofthe cam means.

References Cited UNITED STATES PATENTS 2,672,844 3/l954 Flint 118--3152,878,058 3/ 1959 Gauthier et al. 1118-323 X 3,027,095 3/ 1962 Paasche118-323 X 3,050,416 8/1962 Yahnke et al 118-315 X 3,266,729 8/1966Baskett 239--186 CHARLES A. WILLMUTH, Primary Examiner.

J. P. MCINTOSH, Assistant Examiner.

